Side-swinging article stacker



y 2, 1969 H. J. CA RRELS 3,456,815

SIDE-SWINGING ARTICLE STACKER Filed March 13, 1967 4 sheets-shew; 1

INVEN'ZUR. HOWA /?D J. CMRREL 5' ATTORNEY y 1969 H. J. CARRELS 3,456,815

SIDE-SWINGING ARTICLE STACKER Filed March 13, 1967 4 Sheets-Sheet 2 IN Wm '11 i-:. HOW/4RD J. CA RRELS July 22, 1969 H. J. CARRELS 3,456,815

SIDE-SWINGING ARTICLE STACKER 4 Sheets-Sheet :5

Filed March 13, 1967 INVENTUR. HOW/1RD J. C/MRELS 1W %7//;

July 22, 1969 H. J. CARRELS 3,456,815

SIDE'SWINGING ARTICLE STACKER Filed March 15, 1967 4 Sheets-Sheet 4 m vii/v '1 ma HOW/1RD J. CA RRELS' ATTORNEYS US. Cl. 214-6 7 Claims ABSTRACT OF THE DISCLOSURE A stacking apparatus for elongated articles, such as lumber. Each course of lumber is conveyed to support arms which tilt about a horizontal axis from an inclined receiving position to a horizontal position. The arms are lowered to a plane just above the plane established by the top of the stack, at which time the arms pivot about vertical axes in the same direction through about 90. The articles are stripped from the turning arms and fall onto the top of the stack as the ends of the articles engage a stripping means. This sequence is shown in FIG- URES 3 to 7.

BACKGROUND OF THE INVENTION This invention relates to an article handling apparatus and, more particularly, to an apparatus for stacking generally elongated articles, such as lumber.

In presently operated manufacturing facilities for converting trees to lumber, a large variety of sizes and grades of lumber products are produced. It has become common practice to rapidly sort and gather together those pieces of lumber which have a common grade and size. This is shown in the patent to Boyle, US. Patent No. 3,254,764. While the Boyle sorter does make possible the rapid sorting and gathering of a large variety of lumber sizes and grades without using too much floor space, the resulting lumber sorts must be contained in individual bins, since they are not stacked in a self-supporting package.

Lumber stackers are quite well known which produce a self-supported stack of lumber. Typical of these are the stackers shown in the patent to Thrasher, US. Patent No. 2,878,947, and in the patent to Mason, US. Patent No. 3,169,646. These stackers, however, require rather complex and expensive mechanisms for conveying the lumber to the stacking apparatus and for placing one layer or course of lumber on the stack at one time. It should be noted that in both the Thrasher and Mason installations a great deal of floor space is required for each width of lumber stack. While this floor space requirement for one or two stacks may not amount to much, in a large production facility, where the lumber is stacked in six or twelve or more stacks in accordance with grade and size, this extra floor space requirement would be' intolerable. It is therefore the principal object of the instant invention to provide a stacking apparatus suitable for use in a large lumber sorting line to develop individual self-supporting stacks with a minimum requirement of floor space.

It is another object of this invention to provide an article stacking apparatus which utilizes rugged, fast operating and simple mechanisms for performing its stacking operations.

It is a further object of this invention to provide a stacking apparatus which is adjustable to accommodate a large variation in sizes and lengths of articles to be stacked.

A still further object of this invention is to provide an nited States Patent O improved stacking apparatus which includes means for evening one end of the stack as it is developed.

Other related features and objects of the invention will become more fully apparent as the following description is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIGURE 1 is a perspective view of the stacking apparatus, with some parts removed, illustrating the general arrangement of the components needed to form one stack in accordance with the present invention;

FIGURE 2 is an end elevation view of the stacking apparatus as viewed from the position 2-2 of FIG- URE 5;

FIGURE 3 is a top plan view of the stacking apparatus as viewed from the position 33 of FIGURE 2; and

FIGURES 4 through 7 are side elevation views of the stacking apparatus as viewed from the position 5-5 of FIGURE 3, illustrating its operating cycle in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings with more detail, there is shown in FIGURES 1 to 3 the general arrangement of the stacking apparatus 1. The basic components of the stacking apparatus 1 are the accumulating article feed means 5, the article course or layer supporting means 20, and the article transfer means 30.

The stacking apparatus 1 is supported above the floor by suitable foundation 2. The various components of the stacking apparatus 1 are supported by means of horizontal frame members 3 and vertical frame members 4.

The article accumulating infeed means 5 is similar in overall concept to that shown in US. patent application Ser. No. 512,642, filed Dec. 9, 1965, and now US. Patent No. 3,338,427, in the name of John H. Thedick, having a common assignee with the instant application. A series of sloping supports 7 are equipped with rollers 8 which provide support for the articles, such as lumber 10, being conveyed along the top of the rollers 8 with their longitudinal axes transverse to the direction of movement. The lumber 10 is prevented from further movement by lower stops 12 positioned near the lower end of the conveyor supports 7. In addition, there is a width-sensing means (not shown), such as a photoelectric cell, positioned adjacent the conveyor supports 7 to indicate when there is a sufiicient width of lumber accumulated along the conveyor supports 7 to provide one layer or course of lumber for the stack. In addition, and associated with the width-sensing mechanism, there are upper stop means 16 (shown in FIGURES 4 through 7) which hold the board which is one-too-many for the desired width of the stack, and any others subsequently conveyed from the article sorting means. These boards are thus prevented from continuing down the conveyor supports 7, while the lower stops 12 are moved out of the way, through the action of the stop actuator 14 working through stop linkage 13, permitting the accumulated layer to proceed beyond the end of the conveyor supports 7.

The article course supporting means 20 may be any suitable support and transfer means for the articles, such as the lumber transport mounted on dollies as shown in the before-mentioned Thrasher patent. The preferred construction of the course supporting means 20 is shown in FIGURES 2 through 7 and includes roller support elements 22, which are supported by bearings attached to roll case frame 23. Some of the roller support elements 22 may be driven through suitable roller drive chain 24, which runs in roller drive pulleys 25 mounted on the axes of the rollers 22. Any conventional drive motor may be used to drive the roller drive belts 24 as needed to convey the stack of lumber in the direction parallel with the lumbers longitudinal axis.

While the function and design of the above-described accumulating article feed means 5 and article course supporting means 20 are conventional, the overall improved operation of the instant stacking apparatus is provided through the novel design and mode of operation of the transfer means 30, which functions to receive the articles conveyed from the accumulating article feed means 5 and transfers them one course at a time to the course supporting means 20. The basic components of the transfer means 30 are shown in all of the figures and include course laying arms 31, 32, longitudinal support member 35, miscellaneous drive motors 43, 44, 63, 75 and strippings means 50.

With particular reference to FIGURES l to 3, the features of the course laying arms 31, 32 are noted. The sword-like arms 31, 32 are supported at one end by mounting brackets 37, 38, which include vertical pivot pins 39, 40 which pass through the body of the arms 31, 32 respectively. Keyed to the vertical pivot pins 39, 40 are crank arms 41, 42 which are connected to the piston rods of swing motors 43, 44 respectively. The swing motors 43, 44 are pivotably mounted on the mounting brackets 37, 38 and turn about pivots 45, 46 respectively. Thus, as shown in FIGURE 3, the arms 31, 32 can be moved from the dashed line position, which is generally normal to the longitudinal axis of the lumber 10, through the action of the swing motors 43, 44 to the solid line position parallel to the longitudinal support member 35. It should be noted that the mounting brackets 37, 38 are secured to the longitudinal support member 35 in such a way that the distance between the support arms 31, 32 can be adjusted to accommodate various lengths of articles.

To insure that the boards 10, which are supported on the course laying arms 31, 32, are properly deposited on top of the course supporting means 20 when the arms are pivoted from the position shown in FIGURE 3 in dash lines to the solid line position, there is provided a stripping means 50. This stripping means 50 is also supported and attached at one end to the longitudinal support member 35 in a manner so that it is generally normal to the longitudinal axis of the lumber 10. While the stripping means may be of any suitable shape, as shown, it includes a lower plate 51 and an obstructing endevener plate 52, which is generally normal to plate 51. To establish the relative position of the stripping means 50 with the course laying arms 31, 32, it is useful to consider the upper surface of the course laying arms 31, 32 as defining a first horizontal plane and the bottom surface of the lower plate 51 as establishing a second horizontal plane which is just above and generally parallel to the first horizontal plane. In this manner it can be seen that as the lumber is moved toward the stripping means 50 as a result of the swinging motion of the course laying arms 31, 32 from the dash line position, shown in FIGURE 3, to the solid line position, the ends of the lumber 10 will be engaged by the obstructing endevener plate 52, and the boards 10 will be stripped away from the support of the course laying arms 31, 32.

In order that the lumber 10 can be easily conveyed from the accumulating article feed means 5 onto the course laying arms 31, 32 without some type of heavy retractable extension to the conveyor supports 7, the course laying arms 31, 32 have been mounted in such a way that they may tilt about a horizontal axis running through the longitudinal support member 35. To accomplish this, the longitudinal support member 35 is supported on either end by end plates 55, 56 by means of shafts 57, 58. These shafts 57, 58 are extensions to the member 35 and are pivotably supported in bearing blocks 59, 60 mounted on end plates 55, 56. Crank arm 62 is secured to and extends outwardly from the body of longitudinal support member 35 with 0 .9 end secured to tilt 4 motor 63. When the tilt motor 63 is expanded, it pivots about motor pivot 64 extending from end plate 56. Tilt motor 63 forces crank arm 62 to move in a clockwise direction, as shown in FIGURE 1, moving the course laying arms 31, 32, as well as the stripping means 50, ina clockwise manner upwardly.

In order that the lumber 10, which is stripped from the support of the course laying arms 31, 32, does not fall into a scattered pile, the longitudinal support member 35 is made vertically movable with relation to the course support means 20 in such a way that the upper surface of the last layer 9 of the articles 10 is just below the lower surface of the course laying arms 31, 32 when their pivoting action takes place. It has been found that forvery narrow widths of articles, the tendency for such articles to tumble is eliminated if each of such articles is stripped away from one course laying arm at a different time than it is stripped from the other course laying arm. To accomplish this, hydraulic controls are available which will cause the course laying arm 31 to start its rotation away from beneath the lumber 10 a few moments prior to the start of the rotation of course laying arm 32.

To accomplish the relative movement between the course laying arms 31, 32 and the upper surface of the last layer 9, supported by the course supporting means 20, the end plates 55, 56 are vertically movable through the action of elevation means 65, as shown generally in FIGURE 2. End plate 55 includes guide rollers 67 for guiding the vertical movement of the end plate 55 along vertical guide rail 69, which is secured to vertical frame member 4. In a similar manner, end plate 56 includes guide rollers 68 which engage opposite surfaces of vertical guide rail 70, which in turn is secured to vertical frame member 4. Lifting chains 71, 72 are attached to end plates 55, 56 and pass over suitable sprocket means 74 to be connected to elevation motor 75.

.While conventional limit switches could be used to sense the location of the upper surface of the last layer 9 with relation to the lower surface of the course laying arms 31, 32, it is preferred that an elevation sensing means, including a photo-cell 81 and a target strip 82, as shown in FIGURE 1, are used for this purpose. The photo-cell 81 may be suitably secured to the longitudinal support member 35 in such a way that its light beam corresponds with the lower surface of the course laying arms 31, 32. The target strip 82 may be mounted on the opposite side of the course supporting means 20. As the longitudinal support member 35 is lowered through the action of the elevation means 65, the photo-cell 81 transmits and receives the light which is reflected from the target strip 82, until the light strikes the last layer 9 of .the articles 10 supported by the course supporting means 20. At this time the motor 75 stops operating, and the next layer can be deposited.

Explaining now briefly the operation of the apparatus 1-, reference is directed to FIGURES 4 through 7. As shown in FIGURE 7, the lumber 10 is being conveyed down the rollers 8. The lower stops 12 are in the obstructing position to stop their travel. The boards build up until an electric eye is covered for a set time. This activates the upper stop 16 and deactivates the lower stop 12, as shown in FIGURE 4. Upper stops 16 prohibit any additional boards from being conveyed down onto the course laying arms 31, 32 by the engagement as shown best in FIGURE 5. Once sufiicient time has passed to permit the acccumulated boards to pass from the accumulating article feed means 5 onto the upwardly tilted course laying arms 31, 32, through the action of the tilt motor 63, these arms 31, 32 are tilted downwardly to a horizontal position, as shown in FIGURE 5. At the same time, lower stop 12 is activated and upper stop 16 is deactivated, allowing boards to accumulate resting against lower stop 12.

Through the action of the elevating means 65, the 1011 gitudinal support member 35 and the horizontally disposed course laying arms 31, 32 are lowered from the position shown in FIGURE 5 to that shown in FIGURE 6, until the photo-cell 81 no longer receives the reflection from the target strip 82 and the action of the elevation motor 75 is stopped. Once the action of the elevation motor 75 has ceased, the action of the swing motors 43, 43 begins. As previously indicated, the swing motor 43 may be actuated a moment or two before the actuation of the swing motor 44, so that the course laying arm 31 begins its rotation a bit before the rotation of course laying arm 32. In any event, the boards are moved toward the stripping means 50 by the frictional contact and movement between the boards and the course laying arms 31, 32 as they rotate. With this action, the ends of the articles 10 are evened and made parallel to the surface of the obstruction end-evener plate 52. As the rotation of the course laying arms 31, 32 continues, the boards are no longer supported by the arms 31, 32, and thus each board falls until it makes contact with the upper surface of the last layer 9, which is supported on the course supporting means 20.

Once all of the boards have been stripped from the course laying arms 31, 32, the arms 31, 32 are rotated back to their normal position through the action of the swing motors 43, 44.

With reference to FIGURE 7, the course laying arms 31, 32 are elevated from the position shown in FIGURE 6 through the action of the elevation motor 75, until they reach the position shown in FIGURE 7, at which time the tilt motor 63 is then actuated to pivot the arms 31, 32 upwardly to the position shown in FIGURE 4.

This cycle is repeated until the course supporting means is filled, at which time the roller drive pulley is rotated, through the action of the roller drive chain 24, to move the stack which has been laid upon the roller support elements 22 in a direction longitudinal to the longitudinal axis of the materials stacked.

It is therefore seen that I have disclosed a generally improved article stacking apparatus which is simple in its structure and operation and which utilizes the minimum amount of fioor space for each stack it produces.

What is claimed is:

1. An apparatus for stacking generally elongated articles which comprises in combination: article feed means including conveying means for conveying said articles in a direction normal to the longitudinal length of said articles; article transfer means for receiving articles from said conveying means and including a longitudinal support member substantially parallel to the longitudinal length of said articles, course laying arms pivotably secured to said longitudinal support member to swing about vertical axes between first and second positions in a first horizontal plane, swing motor means for swinging said arms between said first and second positions; stripping means positioned in a second horizontal plane just above said first horizontal plane, substantially normal to said longitudinal support member and adjacent to one of said course laying arms to strip said articles from said arm as it moves from said first to said second position; course supporting means for receiving said articles stripped from said arms and including support elements for supporting said articles in a generally horizontal attitude.

2. The apparatus of claim 1 wherein: said longitudinal support member is rotatably supported by frame means; tilt motor means operatively connected to said longitudinal support member to rotate said support member and said course laying arms from said first horizontal plane upwardly to an incline corresponding substantially to the incline established by said conveying means.

3. The apparatus of claim 1 wherein: said longitudinal support member is supported for vertical movement along vertical support means and is attached to elevation means; said elevation means moving said longitudinal support member relative to said course supporting means and said article accumulating feed means.

4. The apparatus of claim 1 wherein: said longitudinal support member is supported for both vertical movement along vertical support means and tilting movement around its own axis; said longitudinal support member is rotatably supported by elevation means; said elevation means moving said longitudinal support member relative to said course supporting means and said article accumulating feed means; tilt motor means operatively connected to said longitudinal support member to rotate said support member and said course laying arms from said first horizontal plane upwardly to an incline corresponding substantially to the incline-established by said conveying means.

5. The apparatus of claims 1, 2, 3 or 4 wherein: the swing motor means for swinging one of said course laying arms operates to cause said rotation prior to the swing motor means for swinging the other course laying arm.

6. The apparatus of claims 1, 2, 3 or 4 wherein: said course laying arm means are secured to said longitudinal support member by bracket means; and said bracket means is movable longitudinally along said longitudinal support member to change the distance between said course laying arms.

7. The apparatus of claims 1, 2, 3 or 4 wherein: said conveying means includes a first article stopping means at the outer end of said conveying means for stopping said articles when the course laying arms are filled; second article stopping means spaced inwardly of said first article stopping means the distance of a course for stopping said articles from forward movement after the proper number of articles for a course are between it and said first article stopping means; means for rendering said first article stopping means inoperative when a prescribed number of articles are between said first article stopping means and said second article stopping means and when said course laying arms are in position to receive said articles; means for rendering said second article stopping means operative to stop said articles when a prescribed number of articles have been placed between said second article stopping means and said first article stopping means; means for rendering said first article stopping means operative to stop articles after all of said articles have passed from said conveying means to said course laying arms; and means for rendering said second article stopping means inoperative after said first article stopping means are operative to stop articles.

References Cited UNITED STATES PATENTS 626,956 6/1899 Wrightson 198-158 X 1,563,071 11/1925 Brecknell 2l46 X 1,951,178 3/1934 Smitmans 2l4-6 2,562,247 7/1951 Van Schie 2l46 X 2,822,932 2/1958 Patrick 2l46 3,090,503 5/1963 Curtenius 2l4-6 3,338,427 8/1967 Thedick 214-6 3,361,272 1/1968 Carroll 214-6 OTHER REFERENCES German Printed Application, 1,108,145, May 31, 1961.

GERALD M. FORLENZA, Primary Examiner ROBERT J. SPAR, Assistant Examiner US. Cl. X.R. 214-731, 700 

